Bicycles that can be folded have an advantage of a relatively compact arrangement for storage or transport, making them popular with users wishing to reduce storage space, such as commuters, recreation enthusiasts, and campers, among others. Known folding bicycles have a myriad of shortcomings when compared with standard non-folding bicycles. For example, known folding bicycles have a frame of two or more pieces, which can be dismantled, folded or telescopically shortened. In some known folding bicycles, the folded dimensions can be further reduced via removal of their wheels.
In some conventional bicycle folding joints are situated in the central area of the frame, such as within one or more of the down tube, top tube, seat tube and head tube, or bearing tube. A disadvantage of such an arrangement is that the frame's rigidity is reduced, which can detrimentally affect pedaling efficiency, and overall stability.
Another disadvantage associated with such known folding bicycles is that the joints that enable folding can develop a gap, or “play” over a period of usage. This play results in a bicycle that flexes, reducing pedaling efficiency, as the force applied to propel the bicycle is partially absorbed by the flexing joints. In addition, the joints themselves can be weak points in the bicycle, and can cause structural failure, instability or other undesirable riding characteristics.
A further disadvantage is that known folding bicycles have frames that frequently are smaller than the frames of a comparable standard non-folding bicycle. This reduces the ergonomic suitability for a rider. A result of this for many riders is a decrease of the distance that can be ridden with comfort. Riding discomfort can decrease pedaling efficiency, and decrease riding characteristics are less favorable due to the different position of front wheel and smaller wheel size compared to the non-folding bicycles.
Therefore, there exists a need for a folding bicycle that is ergonomically comfortable when riding, optionally has a unitary central frame structure, optionally can be readily folded into a compact arrangement, and/or optionally can maintain its structural rigidity and integrity despite repeated folding and unfolding.